Association between infections caused by multidrug-resistant gram-negative bacteria and mortality in critically ill patients

Table 1 Studies describing mortality in intensive care unit patients with infections caused by multi-drug resistant bacteria vs susceptible

Ref.	Study design	No. of cases	Type of infection	Isolates/resistance definition	Results/comments
Blot et al[35]	Retrospective, cohort study	328	BSI	Variable/ceftazidime-resistance	Antibiotic resistance does not affect the outcome
Peres-Bota et al[36]	Prospective	186	Variable infections	Variable2/at least to ceftazidime, animoglycosides, carbapenems or quinolones	No difference in mortality
Ortega et al[37]	Single center prospective study	53	Colonization and infection	P. aeruginosa/resistant at least to two classes of antibiotics	No difference in mortality
Combes et al[38]	Secondary analysis of a large prospective cohort study	115	VAP	P. aeruginosa/resistance to piperacillin	28-d mortality not associated with piperacillin resistance
Kwa et al[39]	Retrospective cohort study	129	VAP	Variable MDR bacteria/resistance to all available systemic antibiotics	MDR was associated with a higher likelihood of infection-attributed mortality
Playford et al[9]	Retrospective case-control study	197	Variable (including colonization)	A. baumannii/susceptible only to amikacin and colisin	Positive association with increased hospital mortality
Daniels et al[40]	Retrospective, propensity-matched cohort study	84	Variable infections	A. baumannii/resistance to 3 or more classes of antibiotics	No difference in 28-d mortality
Parker et al[41]	Secondary analysis of a randomized trial	739	VAP	P. aeruginosa or variable MDR bacteria2/resistance to 2 or more classes of antibiotics	Higher 28-d ICU and hospital mortality
Pinheiro et al[42]	Retrospective case–control study	131	Variable infections	P. aeruginosa/multi- or pandrug resistant	No association with mortality
Katsaragakis et al[43]	Prospective observational study in a surgical ICU	60	Variable infections	A. baumannii/susceptibility only to colistin	Multi- resistance not associated with mortality
Routsi et al[44]	Prospective observational study	96	BSI	A. baumannii/carbapenem resistance	No association with mortality
Mouloudi et al[45]	Double case -control study	59	BSI	K. pneumoniae/carbapenem resistance	Positive association between KPC producing K. pneumoniae and mortality
Michalopoulos et al[46]	Retrospective case-control study	84	Primary BSIs	K. pneumoniae, A. baumanni, P. aeruginosa/resistance to at least 4 out of 7 antibiotic classes	Higher hospital mortality, compared to controls
			(78% ICU-acquired, 22% ward-acquired)
Lambert et al[47]	Multicenter prospective cohort study	119699	Pneumonia,	E.coli, A. baumannii, P. aeruginosa, S. aureus/resistance to 3rd generation cephalosporins, ceftazidime, and oxacillin, respectively	The additional effect of the most common antimicrobial resistance patterns on mortality is comparatively low
Tabah et al[48]	Prospective multicentre cohort study	1156	BSI BSI	Multiple isolates2/according to the ESCMID	Resistance is associated with increased 28-d mortality
Patel et al[49]	Prospective cohort matched case- control	298	Variable infections	A. baumannii, K. pneumoniae, P. aeruginosa/susceptible to ≤ 1 antimicrobial agent	Resistance not associated with mortality
Zilberberg et al[50]	Single center retrospective cohort study	1076	BSI	Variable gram-negative/Paeruginosa resistant to at least 3 antimicrobials, ESBL, CPE	Impact of MDR on inappropriate therapy/indirect effect on increased hospital mortality
Shorr et al[51]	Retrospective cohort study	131	BSI	A. baumannii/carbapenem resistance	Impact of carbapenem resistance on inappropriate therapy/indirect effect on mortality
Papadimitriou–Olivgeris et al[52]	Single center study	273	Variable infections	K. pneumoniae/resistance to gentamicin, colistin and/or tigecycline	Positive association with mortality
Dabar et al[53]	3-center, prospective cohort study	120	Variable infections	Variable pathogens/MDR P. aeruginosa: Resistance to at least 3 of the following: Pseudomonas acting beta-lactams, carbapenems, aminoglycosides, and quinolones	MDR P. aeruginosa infection was independent risk factor for mortality
Dautzenberg et al[30]1	2-center prospective cohort study	132	Colonization	CPE	Higher hazard of dying (primarily because of an increased LOS)
Bass et al[54]	Prospective case-control study	168	BSI	Gram-negative bacteria/carbapenem resistance	Increased mortality/combination therapy was associated with improve survival rate
Vardakas et al[55]	Retrospective	140	Variable infections	K. pneumonia/carbapenem resistance	No difference in mortality
	Cohort study
Martin-Loeches et al[56]	Prospective observetional study		VAP and HAP	Variable/according to CDC/ECDC	Patients with MDR bacteria had a higher mortality than those with no-MDR

¹Colonization only;

²Gram–positive included. BSI: Blood stream infection; VAP: Ventilator associated pneumonia; MDR: Multidrug-resistant; ESCMID: European Society of Clinical Microbiology and Infectious Diseases; CPE: Carbapenem – producing enterobactaeriacae; ESBL: Extended spectrum beta lactamases; HAP: Hospital acquired pneumonia; ECDC: European Centre for Disease Prevention and Control; CDC: Centers for Disease Control and Prevention.